Conventionally, it has been desired to reduce the installation space of image forming apparatuses such as copying machines, printers, and facsimile machines, as well as compound machines that are provided with a plurality of these functions.
In response to this desire, image forming apparatuses have been developed in which the feeding portion (paper cassette) is arranged in a lower portion and the original capturing portion (scanner portion) is arranged in an upper portion, while the image forming portion (printer portion) and the discharge portion (discharge tray) are provided between the feeding portion and the original capturing portion. That is, with these image forming apparatuses, a reduction in the apparatus installation space is achieved by providing the discharge tray such that it does not protrude laterally from the apparatus. Furthermore, with these image forming apparatuses, the feeding portion, the original capturing portion, and the image-forming portion are arranged in an approximate square-cornered reverse “C” shape when viewed from the front of the apparatus. In this structure, the discharge portion is configured as an empty intermediate space that opens laterally (one side of the square-cornered reverse “C” shape is open), and printed sheets that are discharged to this empty intermediate space are taken out from the front side or a lateral side (the above-mentioned open side).
However, with this type of image forming apparatus, since visibility is poor for the printed sheets that are discharged to the empty intermediate space, it has been a matter of concern that the user forgets to take out printed sheets or leaves some sheets behind.
Techniques are disclosed in JP H06-115794A (hereinafter referred to as patent document 1) and JP H08-339107A (hereinafter referred to as patent document 2) as ways to solve this fault.
First, in patent document 1, a structure is disclosed in which a rotational movement means is provided in a plurality of discharged paper piling means (a unit of discharged paper trays) in order to achieve overall space savings in an apparatus in which the discharge portion does not protrude from the apparatus. In this structure, after discharge of the paper has been completed, the plurality of discharged paper piling means are rotationally moved as a whole in a horizontal direction.
On the other hand, in patent document 2, in order to improve visibility of the printed sheets that are discharged to the discharge portion in an image forming apparatus provided with a so-called internal discharge-type recording medium discharge mechanism in which only the front side of the apparatus is open, a structure is disclosed that aims to improve visibility of printed sheets by arranging an illuminating lamp at an upper portion of an inner side of the discharge portion such that the illuminating lamp is caused to automatically light up when the discharge of a printed sheet is detected.
However, there is a limit to the device miniaturization that can be achieved with either of these patent documents, and both involve increased complication of control operations by a control portion. That is, with these techniques, a space is required for the discharge portion that is substantially equivalent to the size of the maximum length sheet of the plurality of sheet sizes that are used in the apparatus. For example, in an apparatus using an A3 size (297 mm×420 mm) sheet, 420 mm or more is required for the length of the discharge portion and since a size smaller than this size cannot be achieved, it is not possible to achieve further compactness. The reason for this is that when the space of the discharge portion is made smaller than the size of the maximum length sheet, the sheets become folded over (so-called “back bending”) inside the discharge portion in these internal discharge-type apparatuses, thus posing the risk of frequent paper jams.
The embodiments of the present invention have been devised in consideration of these issues, and it is an object thereof to provide a recording medium discharge mechanism that is provided with a discharge space into which a recording medium that has undergone image formation is discharged and that is capable of achieving device compactness and control operation simplification, and an image forming apparatus provided with the recording medium discharge mechanism.